McDermott Will & Emery partner Yar Chaikovsky scored a nice win for Yahoo Inc. and Twitter Inc. last month. The companies were two of the biggest targets among some 100 companies sued for patent infringement in federal courts around the country by an arm of Acacia Research Corp. The Judicial Panel on Multidistrict Litigation consolidated the cases before U.S. District Judge Joan Lefkow of the Northern District of Illinois, and Chaikovsky played a leading role in persuading her that messaging, as described by the inventor in 1995, referred to inbound audio, fax or data file transfers, not Web-based email. Following Lefkow’s 2013 ruling, patentees Unified Messaging Solutions LLC and Advanced Messaging Technologies Inc. stipulated last month to noninfringement for purposes of appeal. We spoke with Chaikovsky about the challenge of litigating a sprawling patent case in a post-America Invents Act world.

Q: How did this litigation come about?